Electric switching apparatus



Aug. 11 1925.

1.. c; NICHOLSON ELECTRIC SWITCHING APPARATUS Filed Sept. 19, 1921 5Sheets-Sheet l glvwemtoz V a. W 3371 elf EH42 Aug. 11, 1925. 1,549,679

L. c. NICHOLSON ELECTRIC SWITCHING APPARATUS Filed se t. 19, 9 sSheets-Skieet :5

Elvwemtoz in c .M 351;; a r tom y W W Aug 1 1, 1925.

7 1,549,679 L. C. NlCHOLSQN ELECTRI C SWI TCHING APPARATU 5 Filed Sept.19, 1921 S Sheets-Sheet 4 I amvewtoz 4 WM 351 auto (M WWW Aug. 11, 1925.1,549,679

L. c. NICHOLSON ELECTRIC SWITCHING APPARATUS Filed Sp't. 19, 1921 sSheets-Sheet 5 Patented Aug-11, 1925.

UNITED STATES LLC YYD C. NICHOLSON, OF EDEN, NEW YORK.

ELECTRIC SWITCHING APPARATUS.

Application filed. September 19, 1921. Serial No. 501,737.

To all whom it may concern:

Be it known that I, LLoYn G. NIoHoLsow, a citizen of the Uni-tedStates,and a resident of Eden, in the county of Erie and State of New York,have invented certain new and useful Improvements in Electric, SwitchingApparatus, of which'the following is a specification.

My invention relates to improvements in electric switching apparatus andis particularly adapted to the openings of alternating current hightension circuits such as those on which a voltage of 10,000 volts orover exists, although it may be used to advantage on lower voltagecircuits carrying heavy currents. One object of the inven- .tion is toprovide a switch which is extremely quick in action. When used to itsfullest extent the invention will provide for the operation of thecircuit breaker in less than one-twenty-fii'th of a second, when a shortcircuit occurs on the line, so that the short circuit may be eliminatedwithout disturbing the operation of rotating synchronous machinery onthe connected system.

My present invention is in some respects an improvement upon thatdescribed in my Patent No. 1,402,310, for electric switching apparatus,issued Jan. 3, 1922. The said.

patent covers a construction in which the use of oil in which'a circuitbreaks is avoided whereby the possibility of theproduction of explosivevapors is done away with. In the invention covered by the said patent,as well as in the present invention a pair of switch contacts are causedto separate when the circuit is to be-opened, these contacts by theirseparation causing current to flow through a Vaporizable liquid so thatthe liquid is immediately vaporized with the result that the pressureexerted by the vapors produced causes a rapid further separation of thecontacts.

An object of my present invention is to produce an extremely eiiectiveand comparatively simple device of the character indicated. Furthervobjects consist in the provision of improved details of construc tionand combinations of parts, all of which will more clearly appear fromthe detailed description given below taken in connection respectively onlines 2-2, and 3-3 of-Fig. 1

.Fig. 4 is an endelevation of the apparatus viewed in the direction ofthe arrows I 7 v I I Flg. 5 18 a vertical section taken on line 5 5 ofFig. 3 on an enlarged scale;

Fig. 6 represents a detail of construction shown on an enlarged scale;

Fig. 7 is a partial side elevation of a switch arm with connected parts;

Figs. 8, 9 and 10 are respectively side elevations of a piston rod andupper and lower members of the piston, disassembled; i

Fig. 11 is' a plan View of the lower piston member;

Fig. 12 is a side elevation of the contact member carried by the lowerend of the piston rod;

Fig. 13 is an end elevation of the switch arm shown in Fig. 7 with thecontact carried thereby; and

-Fig. .14 is an end elevation of a portion of the apparatus utilized ina multipole switch embodying a modifiedform of my invention, certainparts being shown in section. 1

Referring to the drawings, the switch, in the embodiment shown in Fig. 1is preferably formed of two units ofwhich the one shown at the rightcontains what I term the gun in which the contact is broken in avaporizable liquid as previously referred to, together with mechanismfor causing the operation of the gun' and other parts while the unit atthe left carries a switch blade and a stopping dash-pot and switchclosing mechanism.

The unit shown at the right comprises a pair of channel irons 58supported upon insulators 55, these insulators having metal capscemented thereto with transversely extending. channel irons 63, 64,secured thereon and supporting the channels 58. The leftha-nd unit isshown as having a frame work formed of a pair of channels 57, which aresupported by transverse channels 53, 54, carried by metal caps which arecemented on suitable insulators 55, the insulators of both the left andright hand units being shown as supported upon a suitable supportingframe 59.

Referring to the righthand unit, a casting 16 is shown as mounted uponthe channels 58. What I term the gun barrel of the switch is mounted onthis casting.

As shown, what I term the gun barrel takes the form of a cylinder 1formed of a suitable insulating material such as fabric impregnated witha phenolic condensation product, this material being of high mechanicalstrength, water proof and a good insulator; As shown in Fig. 5, thecylinder 1 is mounted in andsupported by a short cylindrical member 8screw-threaded on a portion of its periphery and screwed into positionwithin a cylindrical member 9, the internal diameter of which is greaterthan that of the cylinder 1. Member 9 is formed with a bottom closuremember 9- which may be bolted or otherwise secured on the casting 16.

The contact members which are to be separated when the circuit is to bebroken are mounted within the cylinder or gun barrel 1. A iston head 4is mounted on the stem 7 which extends o'utof the upper end ofthecylinder 1, the contact member 5 being screwed on the lower end of stem7. The lower contact is. provided by the upper end ofrod 6 which extendsup througha suitable stufling box 11 in the bottom portion 9 of thecylindrical member 9, the upper end of rod 6 and the bottom of contactmember 5 normally being pressed together to form a good electricalcontact. A chamber 9 is provided by cylindrical member 9 into whichwater or other va orizable liquid may be supplied, the liquid extendingup into the interior of cylinder 1 to a point above the plane in whichthe contact members 5 and 6 engage. When contact members 5 and 6 areseparated from each' other the water within the cylinder 1 immediatelyacts as a conductor between said switch contact members and the currentflowing through the wa ter causes it to be rapidly vaporized to steam,and the pressureof the steam causes the piston 4 and associated partsoperating in cylinder 1 of the gun to be shot out'of the gun with greatforce and rapidity.

The operating solenoid 23 is mounted on the transversely extendingchannel 64, be-.

tween the two channels 58. The core 22 of solenoid 23 is connected by alink 20 to a' bell crank21 which is pivoted on pin 10 supported bybrackets 10 extending upwardly from the cylinder member 9 of the gunbarrel construction. A spiral spring 67 is coiled about an extension ofpin 10, as

shown in Fig. 3, this spring being arranged to tend to hold core 22 andconnected parts in the position shown in Fig. 5 and to return the sameto such position after the core has been lowered. To produce this resultone end of the spring may be secured to bracket 10 and the other endofthe spring may be suitably secured to bell crank 24;, or to pin 10, thebell crank being? keyed to this pin.

The switch arm 2, as shown in Fig. 1, is pivoted adjacent to'one end asshown at 40, to the brackets42 of the unit shown at the left. Switch arm2, which may take the form of an I beam, as shown, has the piston stem 7secured thereto adjacent its opposite end. As shown (Figs. 5 and 8) thepiston stem 7 may have a pair'of upwardly extending lugs 7 which aresecured to the switch arm 2 by a pin 7, it being understood that currentis adapted to flow from switch arm 2 through lugs 7 or, if desired, by aflexible connection from arm'2, to the piston stem 7 and thence to theswitch contact 5 and rod 6 in contact therewith.

Switch arm 2 likewise carries an auxiliary contact 17 ,which preferablytakes the form of spring fingers brazed to switch arm 2, as shown inFig. 13. Two switchblades 19 are pivotally mounted at their lower endson pin 10 and have contacts at their upper ends adapted to engagebetween the contacts 17.

A stirrup 21 is secured to switch blades 19- and is provided at itsouter end with a cross member 21. A path for current from switch blade 2is provided by contacts 17 and 19 in parallel with the path provided bythe pistonstem 7 contact 5 and rod 6, it being noted that the externalswitch blade 19 may parallel the entire length of the gun barrel 1. Theswitch blades 19 and 17 are provided to carry the load current in excessof that which the contacts 5, 6, would carry.

11811 core 22 moves downwardly by reason of excess current flowingthrough solenoid 23, as will be described hereafter,

the lefthand member 18 of hell crank 24,

(Fig. 5) moves some distance to the right, referring to Fig. 5, and thenstrikes a sharp blow against the cross piece 21 of stirrup 21 so as tosharply disengage switch blades 19 from contacts 17 and break thecircuit extending through members 17 and 19 at this point. A link 25 ispivotally secured at its upper end to a lug formed on bell crank 24, thelowerxend of link 25 being connected by a pin and slot connection with alever 15 which is pivotally mounted at one end to the casting 16. Therodv 6 extends downwardly through the stufiing box 11 at the bottomof-cylinder member 9 of the gun barrel into a cylinder 14, which issupported beneath the bottom member 9 of cylin der 9 by any suitablemeans such as the supporting bolts 14?. A piston 12 is provided withincylinder 14 at the lower end of rod 6, a rod 13 extending downwardlyfrom piston 12 and out throughan opening in the bottom of cylinder 14.

Lever 15 carries at its free end a collar 15 slidably mounted on rod 6immediately above piston 12,- lever 15 operating throug a suitable slot.in cylinder 14. When solenoid 23 is actuated to draw down core 22,

10 the slot in link 25 permitsa certain amount of movement of this linkwithout affecting lever 15, until after-the arm 18 of bell crank 24 hasstruck a hammer blow against cross piece 21 of stirrup 21 to break thecontact between switch members 17 and 19 as described. Thereafter theupper end of the slot in link strikes against the pin 25 which issecured to lever 15 and is slidably mounted in the slot. This results inrod 6' 0 being pushed down 'a short distance to separate contact 5 fromthe upper end of the rod.

The separation of contacts 5 and 6 as.

stated above causes the immediate vaporiza- 25 tion of, the liquid inthe gun barrel, as stated, and the-pressure of the: steam or gas formed,pressing upwardly on .iston 4 forces the piston rapidly out of the gunbarrel. Rod

6 is also rapidly pushed downwards by the pressure of'steam or gas onits upper end, i to the end of its stroke. It will be noted that thefunction of lever 15 and collar 15- is merely to start the motion of rod6 away from contact 5, the motion of rod 6 being,

completed by the steam or gas pressure.

The lower end of rod 13 WhlCl'l extends out of cylinder 14 is .securedto a link .30,

the other end of which is pivotally secured to a bracket 32 extendingdownwardly from '40 channel 64. A spring 31 is connected at one end. tothe channel 63 of the frame of the normal positions. The piston 12 fitsclosely within cylinder 14, the cylinder acting as .a dash-pot todampenand absorb the kinetic energy of rod 6 and connected parts during theoperation of the switch. A rubber bumper 27 is shown as mountedoncasting 16 to be contacted against by bell crank 24 on the downwa" Clmovementof core 22 to stop the moving L .lItS without injury.

The tension on spring? 67 maybe adjusted to prevent the normal oadcurrent through solenoid 23 fro'rngoperatingthe switch, this springbeing overcome when a current in excess of the current for which thespring is adjusted comes over the, line. p

66 The apparatus may be designed to provide for a still larger loadcurrent in which case latching means are provided toprevent any movementof the core 22 and associated parts until a 'current greater than thatfor which the latch operating device is'set comes over the line. Such aconstruction is shown inthe drawings in which, referring to Figs. 1, 3and 5, it will be noted that link 25 is provided adjacent its upper endwith a lug 25 under which the .upper end of a lever 26 normally engagesso as to prevent any downward movement of link 25. pivoted at 26 to thecasting16 and is provided with an outwardly extending tail piece 26(Fig. 3). A solenoid 28 is mounted on the casting 16 beneath tail piece26 and-is Lever 26 is provided with a .core 28 which is drawn upwardlyinto the solenoid when the latter is. energized, the upper end of thiscore then pressing against the under side of tailpiece 26 to push theupper end of lever26 out from under lug 25 so as to unlatch the core 22of solenoid 23 and the connected parts. Solenoid 28, if used, isconnected in series with solenoid 23. Solenoid 28 is relativelysmalland-is-capable of adjustment for practically any current so that it maybe adshown as being provided with a glass water gauge 36, .The reservoiris connected by pipe 34 with the chamber within the cylindrical member 9of the gun barrel. No mechanism is required for regulating the liquidlevel in the reservoir since the switch operates satisfactorily with alarge variation of water level.

Switch blade 2, as stated above, is pivoted at 40 to the brackets 42,the switch blade being keyed to the rotatable pin or shaft 40. Thebrackets 42 extend upwardly from the top of a dash-pot cylinder '45,which is mounted on the frame members 57 of the lefthand unit as shownin Fig. 1. Brackets 42 are provided with guideways 61, as shpwn inFig.2, in which a cross head 66 is slidably mounted. A piston rod 43 issecured near its upper end to cross head 66 and extends downwardlythrough a suitable gland in the cover of cylinder 45. A piston 44 ismounted on the lower end of rod 43, within cylinder 45, which latter isadapted to contain oil or other suitable liquid.

The top of the rod 43 is connected to switch blade 2 in such a mannerthat arm 2 will .be permitted a considerable pivotal movement, upon thebreakin of circuit between contacts 5 and 6 int c .gun barrel,

.inder in before the dash-pot piston '44 is brought into motion. In thepreferred form ofapparatus this connection is made by means of a bentlink 39 which is pivotally connected at one end to the upper end ofpiston rod 43, referring to Fig. 6. The other end of link 39 ispivotallyconnected to switch blade 2 at a point comparatively close to pivot 40.Asshown in the drawings the switch blade 2 may be provided with a saddle41 to which the end of link 39 may be pivoted.

In the operation of this mechanism the link 39 exerts a cam like actionon piston rod 43. When contacts 5 .and 6 separate in the gun barrel thepiston rod 7 and piston 4 will move entirely out of the un barrel 1before thedash-pot piston 44 is rought into motion. The dash-pot, pistonrod and cross head, which are comparatively heavy, are then given agradual acceleration, because of theQcam like action of link 39 onpiston rod 43. The dash-pot cylinder45 is shown as bored with differentdiameters at difi'erent points along itslength, so as tosecureapproximatelyuniform pressure of the oil against piston 44 by varyingthe clearance between the piston and the, walls of the cylproportion tothe speed of the piston. x

Preferably the piston 4'within the gun barrel 1 is so-formed as toprovide a sort of safety valve so that in case of opening a circuit'carrying ,a very large current the excessive sudden steam pressurewithin the gun barrel will be relieved.-

In the preferred form of construction, as

indicated in Figs. 7 to 12 inclusive, the

pistoncomprises an upper part 4 having an upwardly extending sleeveportion 4 which.

is adapted to be slipped over the portion 7 of reduced diameter of thepiston rod 7. A lower piston member 4 is then positioned beneath pistonmember 4 and the contact terminal 5 screwed into'position below that, onthe screw-threaded reduced diameter portion '7 of piston rod 7. Thespring 3 coiled around the piston rod above piston member 4, serves topress the latter tightly against the lower piston member 4. The lowerpiston member is providedwith radial slots 4' and the upper pistonmember 4 is provided with corresponding tongues which are adapted to"fit over the slots 4*. The piston member 4 is also preferably providedwith a pair of openings 4- therethrough and the upper piston member 4 isprovided with -a pair of guide pins 4 which are adapted to seat inopenings 4, so as to align ber 4 directly over the slots 4*. With thisarrangement the piston parts 4 and 4 ordinarily work as a-unit andprevent the escape of steam past the same, spring 3 being qulte strong.If, however, steam of excessive pressure is suddenly generated in thegun the tongues extending around mem-- barrel, the pistonmember 4 willbe raised somewhat against the action of spring 3 so shape, as isindicated at 1 to facilitate the piston 'enteringthe same on the returnof the parts after the actuation of the switch.- It will be noted thatthe piston 4, 4, is not rigidly connected to the piston stem and isarranged to have a slight swinging motion.

about its axis when it enters the gun barrel, to permit it entering thesame without rub- .bing' the inside surface of the barrel.

A pair of levers 46 are fulcrumed intermediate their lengths at theupper ends of a pair of standards 47 which are in turn pivoted at theirlower ends to casting 49 which is secured across the top of framemembers 57 Levers 46 are pivotally connected .at their righthand ends,referring to Fig. 1, to the upper-end of the dash-pot piston 43. At theleftha-nd end of levers 46 the latter are pivotally connected to a pairof vertical members 48, the lower ends of which are attached to acasting 48 secured on top of the insulator 50 which latter has a pin 52of magnetic material extending downwardly I therefrom within a directcurrent solenoid 51. I

When the switch is in its open position, in which the switch blade 2 isthrown upwardly, as shown in Fig.6, the pin 52, constituting the core ofsolenoid 51, is u and will, of course, be drawn down into so enoid 51when the latter is energized-so as to pull down the lefthand end oflevers 46 and raise the righthand end of the same which results inswinging switch blade 2 about its pivot 40 back into position to closethe switch, the piston 7 entering the gun barreluntil contact 5 engagesfirmly against the upper end of rod 6. Thesolenoid 51 is aided in thismovement by spring 65 which, as shown in Fig. 2, is wound about pivotpin 40 and is so connected to pin 40 and to the switch blade 2 as totend to press the switch blade into its closed osition, shown in Fig. 1.Solenoid 51 may e energized by manual control, or automatically.

The operation of the parts has been made clear to a considerable extentin connection with the preceding description. When the normal loadcurrent is flowing, the line current flows from the terminal 71 onbracket 42, shown in Fig. 2, through a flexible connection to shaft 40and thence through the switch blade 2. The current flows 1n one pathfrom switch blade 2 through piston rod 7 contact 5, rods 6 and13, link30 to the frame'members 32, 58 and 64, and thence through solenoid 23,one terminal of which is connected to a frame member 58, to the machineand thence through solenoid 23 to i the ter inal 23 When the latchoperating solenoi 28 is used the latter may be connected in series inthe path just described as by connecting the same between the sole-,

noid 23 and'the frame member 58.

I When an undesirable overload occurs on the line, as for example ashort circuitdue to an insulator failure or an are on the line, theincrease in current in solenoid 23 causes it to pull down its core andopen the switch- 17 19, whereupon all of the current is caused to flowthrough the shunt path through contact members 5 and 6. As the, core 22descends further collar 15 on lever 15 depresses rod 6 so that the upperend of rod 6 is separated from. contact 5. The current flowing acrossthe gap between members 5 and 6 rapidly vaporizes the water within thegun barrel to form steam and the steam pressure immediately forcespiston 4 and associated parts rapidly out of the'gun barrel and forcesrod 6 downwardly, rapidly and completely breaking the line circuit.

Any arc tending to form between contacts 5;

and 6 is extinguished or prevented from forming due to the high pressureof the steam. Furthermore the fact that the con 1 tacts are separatedwith great speed and in the presence of water or in a semi-conductingmedium tendsto prevent the formation of an arc. The switch blade 2swingsupward rapidly without retardation until after the piston 7 hasbeenfthrown entirely out of the gun barrel after whichthe cam link 39becomes effective to depress the dashpot piston 44 whereupon the movingparts of the dash-pot construction are gradually vbrou ht into motion,the kinetic energy of switc blade 2 being thus absorbed and this memberbrought to rest.

Thereupon, or as soon as solenoid 5-1 is energized, switch blade 2 isswungback into operative position, piston4 agam entering the gun barreland contact 5 coming into engagement with the upper end of rod. 6

- which has been moved upwardly into operative position, as soon as theinertia of its downward movement has been overcome, by

spring, 31, while at the same time spring 67 serves to raise core 22 andbell crank 24 into operative position, the arm 18 ofbell crank 24striking against the rear cross piece 21 of stirrup 21 to force switchblades 19 back into engagement with switch contacts 17..

The apparatus operates so rapidly that the circuit 1s opened and theoverload or short circuit switched ofi the line before the rotatingsynchronous machinery on parallel connected systems will get out of stepor lose its load. On the deenergizing of solenoid 28, when the circuitis broken between contact 17 and 19 latch lever 26 swings back intoposition to again engage beneath lug 25 when link 25 again rises to theposition shown in Fig. 5.

' The same principles of operation may be carried out in connection witha multipole switch, as is indicated in Fi 14. As many switches asdesired, such or example as three, may be employed, each of the samebeing similar to the switch mechanism which has been described. Each ofthese will be provided with a switch blade 2 pivotally mounted on ashaft 40 these elements corresponding to the switch blade 2 and theshaft 40 previously described. As is shown in Fig. 14 shafts 40 areextended towards each other in alignment and are connected together bysuitable insulators 7 0. As is indicated in Fig. 14, shafts 40 may beprovided with springs correspondmg to the spring 65 previouslydescribed, and all of 4 the other parts of each switch apparatus may bethe same as those already described.

chanically connected together, the opening of the circuit in two phaseswould of course, serve to open the third phase at the same time.

In-connectio-n with the apparatus which has been descrlbed above it maybe noted that the mechanical construction whereby the movement of the.piston 7 out of the gun barrel is permitted to take place withoutretardation, the movement of' the switch blade 2 carrying the piston 7being thereafter gradually brought to rest with a gradual accelerationof the movin parts of the dash-pot, has been found partlcularlyeffective. In this mechanism a rapidly moving fbody, namely the switchblade 2, is

ivoted near one end and is brought to rest y connecting thecomparatively heavy parts of the stopping mechanism to the swingingswitch blade near its pivot point where its motion is comparativelyslow.

It will also be noted that the present construction provides'anarrangement whereby separation between the contacts 5 and 6 is caused totake place rapidly by causing the rod 6 to move downwardly through aconsiderable distance, comparatively speaking,

while the upper Contact has only to move upwardly through acomparatively' short dis tance until it is clear of the gun barrel. Thisarran ement permits the piston to (extend parallel with the throughoutthe entire length of the latter.

into the gun barrel only a comparatively short distance when it is inits operative position. It will also be noted that the auxiliary contactblade 19 extends in un barrel substantially It will also be noted thatthe construction is comparatively simple as to all its parts and ispositive in its operation.

It will be understood that many changes and modifications may be madewithout de-.

parting from the spirit and scope of the invention, the invention notbeing limited to the details shown and described, the scope of theinvention being'indicated by the appended claims.

What I claim is I 1. In switching apparatus, the combina- 1 tion of acylinder open at one end, a piston thereln having its stem extendingtrom said cylinder, a contact carried by said plston, a

therein having its stem extending from saidcylinder, a contact carriedby said piston, a second contact normally in engagement with said first;contact, a pivoted arm'outside said cylinder having the upper end ofsaid piston stem connected thereto and car ried thereby, said contactsbeing included in an electric circuit, said piston being adapted to bemoved rapidly out of said cylinder upon separation of said contacts, a

dash-pot having a piston, and means positione-d to'be actuated by apoint on said pivoted arm near the said dash-pot piston.

3. In switching apparatus, the combinapivot thereof to actuate tion of acylinder open atone end, a pistonq therein having its stem extendingfrom said cylinder, a contact carried by said piston, a second contactnormally in engagement with said first contact, a pivoted arm outsidesaid cylinder having the upper end of said piston stem connected theretoand carried thereby, said contacts being included in an electriccircuit, said piston being adapted to be moved rapidly out of saidcylinder upon separation of said contacts, a dash-pot hav- 1ng a piston,andmeans positioned to be actuated by said pivoted arm .to actuate Saiddash-pot piston only after said first named piston has moved out ofsaid-cylinder.

4. In switching apparatus, the combination of a cylinder open at oneend, a piston therein having its stem extending from said cylinder, acontact carried by said piston, a second contact normally in engagementwith said first contact, a pivoted arm outside said cylinder having theupp'er end of said piston stem connected'thereto and carried thereby,said contacts being included in an electric circuit, said piston beingadapted to be moved rapidly out of said vcylinder upon separation ofsaid contacts, a dash-pot havmg a piston, and a cam linkconnecting saiddash-pot piston with a point on said pivoted arm adjacent thepivotthereof whereby ressure will be exerted .on said dash-pot piston ingradually increasing amount to actuate the same and thereby stop themovement of said ivoted arm.

5. n switching apparatus, the combination of a cylinder open at one end,a piston therein having its stem extending from said cylinder, a contactcarried by said piston, a

second contact normally in engagement therewith, a pivoted arm outsidesaid cylinder having the upper end of said piston stem connected theretoand carried thereby, said contacts being includedv in an electric circuit, said piston being adapted to be moved rapidly out of said cylinderupon -separa; tion of said contacts, an auxiliary switch' member carriedby said arm, a movable switch member adapted to engage therewith, saidswitch members being included in a circuit, inlshunt with said first andsecond contacts, and meansfor moving said movable switch member out ofengagementwith said auxiliary switch member.

6. In switching apparatus, the combination of a cylinder open at oneend, a piston therein having its stem extending from said cylinder, acontact carried by said piston, a second contact normally in engagementtherewith, a pivoted arm outside said cylinder having the upper end .ofsaid piston stem connected thereto and carried thereby, said contactsand arm being included in an electric circuit, said piston being adaptedto be moved rapidly out of said cylinder upon separation of saidcontacts, an auxiliary switch member carried by said arm, and a movableswitch member adapted to engage therewith and to extend parallel to theentire length of said cylinder, said switch members being included in acircuit in shunt with said first and second contacts.

7. Inswitching apparatus, the combination of cooperating switch contactmembers, a piston connectedtooperate one of said members, a cylinder inwhich said piston and said members operate, a solenoid, a switch outsidesaid cylinder in shunt relation to said contact members comprising atact members, a bell crank connected to the core of said solenoid andadapted to strike pivoted contact arm and at contact engaged thereby,means for maintaining a vaporizable liquid about said first mentionedcons a blow upon said pivoted arm to open the switch, upon movement ofsaid core, and means for thereafter, during movement of said core,separating said =first mentioned contact members.

8Q In switching apparatus, the combination of cooperating switch contactmembers, a piston connected to operate one of said members, a cylinderin which 'said piston and said members operate, a solenoid, a switchoutside said'cylinder in shunt relation to said contact memberscomprising a pivoted contact arm having a cross piece se-' cured theretoand a contact engaged by said arm, means for maintaining a vaporizableliquid about said first mentioned contact members, a lever connected tothe core of said solenoid adapted upon movement of said core to move adistance and then strike said cross piece to disengage said pivoted armfrom the contact engaged thereby, and

means 'for thereafter, during movement of said coreyseparating saidfirst mentioned contact members.

9. In switching apparatus, the combination of cooperating switch contactmembers, a piston connected to operate one of said members, a cylinderin whichsaid piston and said members operate, a solenoid, a switchoutside said cylinder in shunt relation to said contact memberscomprising a pivoted contact arm and a contact engaged thereby, meansfor, maintaining a vapor1z able liquid about said first mentioned contact members, a bell crank connected to the core of said solenoid andadapted to strike a blow upon'said pivoted'arm to open the switch uponmovement of said core', and link and'lever connections between said bellcrank and the second of said first mentioned contacts to thereafter,during movement of said core, move said second contact out of engagementwith the first mentioned of said contacts.

10. In switching apparatus, the combination of cooperating switchcontact members, a piston connected to operate one of said members. acylinder in which said piston and members operate, a dash-pot inalignment with said cylinder, a rod'connecting the second of saidcontact members with the 4 thereof, and connections between. the mov-'piston of said dash-pot, means for maintaming a vaporlzable liquid aboutsaid contact members, electro-responsive means having a movable element,a lever extending into said dash pot and engaging-the piston ableelement of said electroresponsive means and said lever for moving thesecond of said contact members out-of engagement with the firstnponmovement of said movable element a piston connected to operate one ofsaid .members, a cylinder in which said. piston and members operate, adashpot 'in alignment with said cylinder, a rod connects ing the secondof said contact members with the piston ofsaid dash-pot, means formaintaining a vaporizable liquid about said contact members,electroresponsive means adapted when the current therethrough ex cee-dsa predetermined value, to separate' said contact members, said partsbeing are ranged to then permit a comparatively long movement of saidrod and second contactmember, and,a shorter movement of said piston andfirst contact member within said v cylinder under the pressure of thevapor generated upon the separation of said contacts.

12. In switching apparatus, the combina- Y tion of cooperating switchcontact members. a piston connected to operate one of said members, acylinder in which said piston and said members operate, a solenoid. aswitch outsidesaid cylinderin shunt relation to said contact memberscomprisinga pivoted contact arm and a contact engaged thereby, aconnectionjbetween the core of said solenoid and said pivoted contact:arm for disengaging the latter from its cooperating contact after saidcore has moved an appreciable distance. upon how of excesscurrentthrough said solenoid. and means, including a lost motion connection forcausing movement of said first mentioned connection to separate saidfirst mentioned con- I tacts after movement of said pivoted contact arm.

' '13. In switching apparatus, the combination of cooperating switchcontact members, a piston connected to operate one of said members,acylin'der in which said piston and said members operate, a solenoidhaving a core, means operated by movement of said core for controllingthe movement ele'ctroresponsibe means in circuit with said solenoidadapted to trip said latch means when a current greater than apredetermined of the other of said contact members, latch means forpreventing movement of said core,

value flows therethrough, and means for maintaining a vaporizable liquidabout said firstmentioned contact members.

Signed at Buffalo in the county of Erie and State of New York, this15'th day of Sept. A. D. 1921.

. LLOYD o. monoLson.

